Reorder min/max_protocol_version descriptions in libpq documentation

Hi,

Commit 285613c60a7 added the min_protocol_version and max_protocol_version
connection options to libpq. However, their descriptions currently appear
in the middle of the unrelated ssl_min_protocol_version and
ssl_max_protocol_version entries in libpq.sgml. Is there a reason for
this placement?

To make the documentation more intuitive and easier to navigate,
I suggest moving these entries after the SSL-related options.
Attached is a patch that does that.

Thanks,

-- 
Fujii Masao
NTT DATA Japan Corporation